Brunt Posted August 12, 2011 Share Posted August 12, 2011 Hello, I recently purchased a sub from in ID company and a reputable one at that. Try to picture this: This company makes a wonderful ported 15" sub which is 500w. They do not normally make one, but they built me a custom 15" sealed sub in a 20" cube, powered by the same 500w. After dialing it in and messing with settings, and even talking to the company...I come to this conclusion: I am completely underwhelmed by the sub's output. During the opening scene of the new Star Trek, there is a a bass heavy passage right after the opening credit. During this scene, before I could even feel or hear actual bass, I heard the driver knocking as it was being over driven. Keep in mind my sub gain was 12:00 and my AVR sub level was set at less than zero. So, after dialing it in per the company's instruction, the sub is now set so it won't make that noise...which is awesome...except that now the overall output and volume is almost worse than my old Polk PSW505. My question to you guys is this: What would make this sub behave this way? Over powered? Underpowered? Keep in mind, the company does sell sealed subs, which usually have more power than their ported cousins...but mine doesn't. I know sealed subs offer less output, but I've read in numerous locations that sealed subs also off the advantage of being incredibly hard to over drive because of the pressure and force being applied to the backside of the driver and it not being able to escape through a port. Any thoughts would be greatly appreciated!!! Quote Link to comment Share on other sites More sharing options...
JasonJCarney Posted August 12, 2011 Share Posted August 12, 2011 Man Brunt, everytime I log on your having another issue! Lol. My advice.... Emotiva XPA-3.... 2 new ported subs.... And a monster sub outlet for them. Quote Link to comment Share on other sites More sharing options...
Brunt Posted August 12, 2011 Author Share Posted August 12, 2011 No doubt...budget route seems to come with it's share of headaches! Quote Link to comment Share on other sites More sharing options...
willland Posted August 13, 2011 Share Posted August 13, 2011 What would make this sub behave this way? Over powered? Underpowered? Keep in mind, the company does sell sealed subs, which usually have more power than their ported cousins...but mine doesn't. I know sealed subs offer less output, but I've read in numerous locations that sealed subs also off the advantage of being incredibly hard to over drive because of the pressure and force being applied to the backside of the driver and it not being able to escape through a port. Any thoughts would be greatly appreciated!!! I don't think(unless they skimped on parts) that your custom sealed sub with 500 watts RMS should behave that way. My "only" 400 watt(1200 watt peak) Paradigm Servo 15a is equipped with distortion(and max output) limiting servo circuitry that is nowhere near underwelming in my 5000+ cubic feet family room(16W x 31L x 12H). It fills my room with tight and explosive bass. Where is your sub located in relation to your main speakers? If they are not on the same plane at an equal distance from your seating position, you may need to tweek the phase control on the sub. Bill Quote Link to comment Share on other sites More sharing options...
Brunt Posted August 13, 2011 Author Share Posted August 13, 2011 We shall see...going to test more extensively today, if nothing changes I pray they take it back! lol Quote Link to comment Share on other sites More sharing options...
psg Posted August 13, 2011 Share Posted August 13, 2011 I'd seek advice of a DIY sub forum, http://www.avsforum.com/avs-vb/forumdisplay.php?f=155 would be a good start. Maybe people there are used to designing sealed and ported subs based on TS driver parameters and would know what to expect. Your situation sounds strange to me, as it does to you. A sealed sub should be much harder to bottom out. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted August 14, 2011 Share Posted August 14, 2011 When you are building a sealed sub, it is very important to use a driver that is suited for a sealed englosure of the volume you need. Also, any leaks will have ill effects. If you want to check for leaks, just use a low frequency test tone around 15Hz or so, and listen for hissing. Another thing; sealed subs tend to not be very good at extreme low frequencies. They are more suited for music. For LFE for movies, I like tuned port or ported subs. Quote Link to comment Share on other sites More sharing options...
MikeFord Posted August 15, 2011 Share Posted August 15, 2011 Hello, I recently purchased a sub from in ID company and a reputable one at that. Try to picture this: This company makes a wonderful ported 15" sub which is 500w. They do not normally make one, but they built me a custom 15" sealed sub in a 20" cube, powered by the same 500w. I heard the driver knocking as it was being over driven. Keep in mind my sub gain was 12:00 and my AVR sub level was set at less than zero. Knocking I would associate with excursion limiting, voicecoil smacking the back plate. Too much power does that, but how much is too much drops rapidly as the signal frequency goes down. A typical sealed box subwoofer rolls off, reduces output, below the frequency the box and woofer are tuned for. Some amp with lots of watts will attempt to compensate with EQ that is the opposite, boosting power, and matching the roll off. Two issues with that, the amount of boost can require some serious power, and there needs to be some kind of low frequency cut off to protect the driver from very low frequency signals. I suspect you amp may not be providing the low frequency cutoff, and/or has too much low frequency boost. For better answers you will need to provide more specifics, driver model used, amp, amp settings etc. Quote Link to comment Share on other sites More sharing options...
Brunt Posted August 15, 2011 Author Share Posted August 15, 2011 Hello, I recently purchased a sub from in ID company and a reputable one at that. Try to picture this: This company makes a wonderful ported 15" sub which is 500w. They do not normally make one, but they built me a custom 15" sealed sub in a 20" cube, powered by the same 500w. I heard the driver knocking as it was being over driven. Keep in mind my sub gain was 12:00 and my AVR sub level was set at less than zero. Knocking I would associate with excursion limiting, voicecoil smacking the back plate. Too much power does that, but how much is too much drops rapidly as the signal frequency goes down. A typical sealed box subwoofer rolls off, reduces output, below the frequency the box and woofer are tuned for. Some amp with lots of watts will attempt to compensate with EQ that is the opposite, boosting power, and matching the roll off. Two issues with that, the amount of boost can require some serious power, and there needs to be some kind of low frequency cut off to protect the driver from very low frequency signals. I suspect you amp may not be providing the low frequency cutoff, and/or has too much low frequency boost. For better answers you will need to provide more specifics, driver model used, amp, amp settings etc. Well, my sub was designed and built by Elemental Designs. The driver is the exact driver they use in their A5-350, a ported, 500w 15" sub that is highly respected for it's output, extension and value. I swapped my driver out and swapped in another, identical driver from a A5-350. My driver sounded great in the A5-350 as it should and the replacement driver sounded the same in my sealed cabinet. The amp is the BASH 500w plate amp found on Parts Express.com The problem I feel lies in the design. Maybe the amp is a bad choice, but it seems to be working fine and the wiring was all done correctly. Also, I can't stress this enough, but before the driver makes that terrible sound and while it's actually happening the output of this sub just plain sucks. I'm thinking the design of this sub wasn't tested or that well thought out, but I'm waiting to hear back from eD to see what my options are. Will keep you guys posted. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted August 15, 2011 Share Posted August 15, 2011 I bet you are right, they made this for you, and basically never tested it. Perhaps they will port the sub for you, and call it even steven?? You didn't want a ported sub, but its better than a door stop. I hope they do the right thing. Best of luck! I'll be staying tuned. Quote Link to comment Share on other sites More sharing options...
formica Posted August 16, 2011 Share Posted August 16, 2011 Where is your sub located in relation to your main speakers? If they are not on the same plane at an equal distance from your seating position, you may need to tweek the phase control on the sub. Bill Sounds like the phase may be inversed (externally or internally) ... Or some cancelations occurring... Quote Link to comment Share on other sites More sharing options...
MikeFord Posted August 17, 2011 Share Posted August 17, 2011 I'm don't know this amp much at all, but it seems to me its setup for something like 5 DB of boost around 20 hz, which saps a lot of power for subsonics and could make a driver smack. I think this may be the key, http://www.parts-express.com/pdf/300-752.pdf Quote Link to comment Share on other sites More sharing options...
JasonJCarney Posted August 18, 2011 Share Posted August 18, 2011 That's interesting. I wonder why eD used that amp and not their LT500. Did you get an answer as to what kind of testing was preformed on it before they shipped? Has this problem been resolved Brunt? Quote Link to comment Share on other sites More sharing options...
Ironsave Posted August 18, 2011 Share Posted August 18, 2011 Brunt, Wow; that SUCKS. I hope they do right by you. I have always thought highly of this company........ Most newest generation sealed subs have limit circuitry which prevents the sub bottoming out. (The Emo U 12 does). I would not want to have my system cranked for friends over watching a movie and have that start happening!!! Quote Link to comment Share on other sites More sharing options...
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